Patient specific guides

ABSTRACT

A device for an orthopedic knee procedure. The device includes a drill guide having a body portion and first and second posts extending from the body portion, the first and second posts defining first and second internal through-bores, the first post having a first cross-sectional shape and the second post having a second cross-sectional shape different than the first cross-sectional shape of the first post.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation-in-part of U.S. patent applicationSer. No. 11/756,057, filed on May 31, 2007, which claims the benefit ofU.S. Provisional Application No. 60/812,694, filed on Jun. 9, 2006.

This application is also a continuation-in-part of U.S. patentapplication Ser. No. 11/971,390, filed on Jan. 9, 2008, which is acontinuation-in-part of U.S. patent application Ser. No. 11/363,548,filed on Feb. 27, 2006.

This application is also a continuation-in-part of U.S. patentapplication Ser. No. 12/038,849, filed on Feb. 29, 2008, which is acontinuation-in-part of U.S. patent application Ser. No. 12/025,414,filed on Feb. 4, 2008, which claims the benefit of U.S. ProvisionalApplication No. 60/953,637, filed on Aug. 2, 2007.

The disclosures of the above applications are incorporated herein byreference.

INTRODUCTION

Various custom made, patient-specific orthopedic implants and associatedtemplates and guides are known in the art. Such implants and guides canbe developed using commercially available software. Custom implantguides are used to accurately place pins, guide bone cuts, and insertimplants during orthopedic procedures. The guides are made from apre-operative plan formed from an MRI or CT scan of the patient and relyon matching a subcutaneous anatomic feature for correct positioning.

The present teachings provide drill guides and associated patientspecific alignment guides.

SUMMARY

The present teachings provide a device for an orthopedic knee procedure.The device can include a drill guide having a body portion and first andsecond posts extending from the body portion, the first and second postsdefining first and second internal through-bores, the first post havinga first cross-sectional shape and the second post having a secondcross-sectional shape different than the first cross-sectional shape ofthe first post.

In another aspect, the device of the present teachings can include atibial drill guide having a body portion and first and second postsextending from the body portion, the first and second posts definingfirst and second internal through bores with circular cross-sections,the first post having a first cross-sectional shape and the second posthaving a second cross-sectional shape different than the firstcross-sectional shape of the first post. The device can also include apatient-specific tibial alignment guide. The alignment guide can includea body with an inner anatomy-engaging surface shaped to closely conformand mate with a corresponding tibial joint surface, and a single guidingreceptacle defining an inner channel sized and shaped to non-rotatablyreceive the second post of the tibial drill guide. When the alignmentguide is mounted on the tibial joint surface and the drill guide ismounted on the alignment guide, the first post remains exposed outsidethe alignment guide and provides clearance for a patellar tendon. Thefirst post is at a fixed orientation relative to the single guidingreceptacle.

In a further aspect, the device of the present teachings can include atibial drill and a patient-specific tibial alignment guide. The drillguide can include a body portion and first and second posts extendingfrom the body portion, the first and second posts having circularcross-sections, the first and second posts defining first and secondinternal through bores with circular cross-sections, the first posthaving a longitudinal length shorter than a longitudinal length of thesecond post. The alignment guide can include a body with an inneranatomy-engaging surface shaped to closely conform and mate with acorresponding tibial joint surface, and first and second guidingreceptacles defining first and second inner channels sized and shaped toreceive the first and second posts of the tibial drill guide. The firstreceptacle can be shorter in length than the second receptacle, suchthat when the alignment guide is mounted on the tibial joint surface andthe drill guide is mounted on the alignment guide, the first receptacleand the first post define a clearance gap between the tibia and thedevice for a patellar tendon.

The present teachings provide a method that includes providing a drillguide having a body portion and first and second posts extending fromthe body portion, the first and second posts defining first and secondinternal through bores, the first post having a first cross-sectionalshape and the second post having a second cross-sectional shapedifferent than the first cross-sectional shape. The method also includesproviding a patient-specific tibial alignment guide, the alignment guideincluding a body with an inner surface shaped to closely conform andmate with a corresponding tibial joint surface, and a single guidingreceptacle defining an inner channel. The method further includesmounting the alignment guide on the tibial joint surface, engaging theinner surface to the tibial joint surface, positioning the guidingreceptacle on a medial side of the tibial joint surface, mounting thedrill guide on the alignment guide, non-rotatably inserting the secondpost in the inner channel of the guiding receptacle, and placing thefirst post medially and closely to a patellar tendon without interferingwith the patellar tendon.

In another aspect, the method includes providing a tibial drill guidehaving a body portion and first and second posts extending from the bodyportion, the first and second posts having circular cross-sections, thefirst and second posts defining first and second internal through bores,the first post having a longitudinal length shorter than a longitudinallength of the second post. The method also includes providing apatient-specific tibial alignment guide, the alignment guide including abody with an inner anatomy-engaging surface shaped to closely conformand mate with a corresponding tibial joint surface, and first and secondguiding receptacles defining first and second inner channels, the firstreceptacle being shorter in length than the second receptacle. Themethod further includes mounting the alignment guide on the tibial jointsurface, engaging the inner surface of the alignment guide to the tibialjoint surface, positioning the medial guiding receptacle on a medialside of the tibial joint surface, mounting the drill guide on thealignment guide, inserting the first and second posts in thecorresponding first and second inner channels of the guiding receptacle,and providing a clearance between a tibial tuberosity and firstreceptacle and first post for a patellar tendon.

Further areas of applicability of the present teachings will becomeapparent from the description provided hereinafter. It should beunderstood that the description and specific examples are intended forpurposes of illustration only and are not intended to limit the scope ofthe present teachings.

BRIEF DESCRIPTION OF THE DRAWINGS

The present teachings will become more fully understood from thedetailed description and the accompanying drawings, wherein:

FIGS. 1-3 are perspective views of a drill guide according to thepresent teachings;

FIGS. 4-5 are perspective views of a drill guide according to thepresent teachings;

FIG. 6 is a perspective view of a patient-specific alignment guideaccording to the present teachings;

FIG. 7 is a perspective view of the patient-specific alignment guide ofFIG. 6 shown with the drill guide of FIG. 1;

FIG. 8 is a perspective view of a patient-specific alignment guide shownwith a drill guide according to the present teachings;

FIGS. 9-11 are perspective views of a drill guide according to thepresent teachings;

FIG. 12 is a sectional view of the drill guide of FIG. 11 taken alongline 12-12;

FIG. 13 is a side view of the drill guide of FIG. 11;

FIGS. 14-16 are perspective views of a patient-specific alignment guideaccording to the present teachings;

FIGS. 17 and 18 are environmental views of the patient-specificalignment guide of FIG. 14 shown on a tibia; and

FIG. 19 is an environmental view of the patient-specific alignment guideof FIG. 14 and the drill guide of FIG. 9 shown on a tibia.

DESCRIPTION OF VARIOUS ASPECTS

The following description is merely exemplary in nature and is in no wayintended to limit the present teachings, applications, or uses. Forexample, although the present teachings are illustrated for alignmentguides in knee surgery, the present teachings can be used for otherguides, templates, jigs, drills, rasps or other instruments used invarious orthopedic procedures.

The present teachings generally provide patient-specific alignmentguides and associated drill guides for use in orthopedic surgery, suchas in knee arthroplasty, for example. The patient-specific alignmentguides can be used either with conventional or patient-specific implantcomponents prepared with computer-assisted image methods. Computermodeling for obtaining three dimensional images of the patient's anatomyusing MRI or CT scans of the patient's anatomy, the patient specificprosthesis components, and the patient-specific guides and templates canbe provided by various CAD programs and/or software available, forexample, by Materialise USA, Ann Arbor, Mich.

The patient-specific alignment guides are generally formed usingcomputer modeling based on the patient's 3-D anatomic image and have aninner engagement surface that is made to conformingly contact and matcha three-dimensional image of the patient's bone surface (with or withoutcartilage or other soft tissue), by the computer methods discussedabove. The patient-specific alignment guides can include custom-madeguiding formations, such as, for example, guiding bores or cannulatedguiding posts or cannulated guiding extensions or receptacles that canbe used for supporting or guiding other instruments, such as drillguides, reamers, cutters, cutting guides and cutting blocks or forinserting pins or other fasteners according to a surgeon-approvedpre-operative plan. The patient-specific alignment guides can be use inminimally invasive surgery, and in particular in surgery with multipleminimally-invasive incisions. In one aspect, the drill guides caninclude guiding cannulated or tubular legs that can be received in theguiding bores of the alignment guides for drilling therethrough, asdiscussed below.

The patient-specific alignment guides and the associated drill guidescan be structured to provide or define a clearance for tendons,ligaments or other tissues associated with the joint. In the exemplaryillustrations of FIGS. 1-19, various alignment guides 300 and drillguides 100 are structured to have specific geometric features foravoiding a tendon associated with the tibia of the knee joint, whileenabling the placement of a drill as close to the tendon as determinedby the surgeon and while maintaining an alignment relative to the jointas determined by the pre-operative surgical plan. A first aspect of thepresent teachings is discussed in connection with FIGS. 1-8, and asecond aspect in connection to FIGS. 9-18.

Referring to FIGS. 1-5, an exemplary drill guide 100 according to thepresent teachings includes a body portion 102, a cylindrical handleportion 104, a first or medial cannulated post 106 extending from thebody portion 102 and defining an inner bore 112 for guiding a pin or adrill bit, and a second or lateral cannulated post 108 extending fromthe body portion 102 and defining an inner bore 110 for guiding a pin ora drill bit. The first post 106 can be a medial post relative to thesecond post or relative to the patient's anatomy, and the second post108 can be a lateral post relative the patient's anatomy. The innerbores 112 and 110 can have circular or non-circular cross-sections andcan be configured for receiving drill bits or pins. The first and secondposts 106, 108 can have cross-sectional areas of different shapesrelative to one another.

Referring to FIGS. 1-3, the second post 108 can be shaped to have anouter surface 109 having a cross-section in the form of a keyhole, i.e.a shape that includes a cylindrical portion 127 and a prismatic portion129 extending radially from the cylindrical portion, as shown in FIG. 3,although the outer surface 109 can have other shapes that can increasethe rotational stability and prevents rotation of the drill guide 100,when the drilling guide 100 is mounted on an alignment guide 300, asdiscussed below.

Referring to FIGS. 5 and 6, the second post 108 can have a cross sectionin the shape of a rectangle, for example. The second post 108 can have across-section with larger cross-sectional area than the cross-sectionalarea of the first post 106. The second post 108 can also be bigger inoverall size and dimensions than the first post 106.

Referring to FIGS. 6-8, alignment guides 300 for use with the tibia areillustrated. The alignment guide 300 can include a body portion 302having an inner anatomy-engaging surface 304, which is molded orotherwise shaped to closely conform in substantially mirror-like mannerto the surface of the joint anatomy of the patient, in this particularexample, the tibia with or without associated soft tissue, depending onthe patient and the surgical procedure. The alignment guide 300 isplaced on the lateral side of the proximal joint surface of the tibia80, such that the inner surface 304 conforms to proximal and anteriorportions of the lateral side of the tibia 80, as shown in FIGS. 17-19.The alignment guide 300 can also include an elongated arcuate arm 310having first and second ends 309, 311, the first end 309 attached to theouter surface of the body portion 302, and the second end 311 engageablewith the tibia. The arm 310 can arch and extend away from the bodyportion 302 and provide a handle for manipulating the alignment guide300. The second end 311 of the arm 310 can provide a stabilizing surfaceengaging the tibia.

The alignment guide 300 can include one or more guiding receptacles, theprecise location of which is determined on the basis of a pre-operativesurgical plan for locating alignment pins and assisting in locatingdrilling and/or cutting instruments for resecting and shaping the jointfor receiving a prosthetic implant, as described in commonly-owned,co-pending in U.S. patent application Ser. No. 11/756,057, filed on May31, 2007, incorporated herein by reference. The alignment guides 300illustrated in FIGS. 6-8 include a single guiding receptacle 308, whilethe alignment guide 300 illustrated in FIGS. 14-19 includes two guidingreceptacles 306, 308.

The alignment guide 300 can include a lateral guiding receptacle 308extending from the body portion 302 on a lateral side relative to thetibia. The guiding receptacle 308 can enclose and define an innerchannel 318 having a cross-section shaped and sized to receive thecorresponding lateral post 108 of the drill guide 100, as shown in FIGS.6-8. A channel 318 having a keyhole-shaped cross-section for receivingthe keyhole-shaped lateral post 108 of the drill guide 100 in a keyed ornon-rotatable manner is illustrated in FIGS. 5 and 6. A channel 318 withan elongated rectangular cross-section for non-rotatably receiving therectangularly-shaped lateral post 108 of the drill guide is illustratedin FIG. 8. As can be seen from FIGS. 7 and 8, the medial post 106 of thedrill guide 100 is remains exposed outside the alignment guide 300, suchthat when the alignment guide 300 engages the tibia, the medial post 106is exposed outside and not engaged with the alignment guide 300, therebyproviding clearance for the patellar tendon that connects to the tibialtuberosity, which is shown at 82 in FIG. 18 in connection with adifferent aspect of the present teachings discussed below. Further, theunencumbered exposed medial post 106 can be placed axially as close tothe patellar tendon as determined by the surgeon without beingobstructed by the alignment guide 300, while maintaining a fixedorientation relative to the guiding receptacle 308 of the alignmentguide 300. The location of the medial post 106 relative to the tibia ispredetermined by the location of the lateral post 108, which in turn ispre-determined by the channel 318 of the alignment guide on the basis ofa preoperative surgical plan.

The shape and size of the cross-sectional area of the keyhole-shaped orrectangular lateral post 108 of the drill guide 100 is keyed to lateralreceptacle 308 of the alignment guide 300 fixing the location andorientation of both lateral and medial posts 108, 106 and providingrotational stability to the drill guide 100, when the lateral post 108is received in the corresponding channel 318 of the lateral receptacle308 of the alignment guide 300. In this respect, the shape of thelateral post 108 aligns the drill guide in a keyed manner to thealignment guide 300, providing rotational stability and providingresistance against rotation, such that the medial post 106 can be remainexposed and unsupported by the alignment guide 300 during drillingthrough the drill guide 100 to provide clearance for the patellar tendonwhile maintaining the orientation and location of the lateral and medialposts 108, 106 predetermined by the alignment guide 300 on the basis ofa pre-operative plan, as discussed above.

Referring to FIGS. 9-18, a drill guide 100 having lateral and medialposts 108, 106 is illustrated in FIGS. 9-13 for use with a correspondingalignment guide 300 having corresponding lateral and medial receptacles308, 306 with cylindrical channels 318 and 316, as shown in FIGS. 14-19.

Referring to FIGS. 9-13, both the lateral and medial posts 108, 106 ofthe drill guide 100 can be cylindrical with circular cross-sections, butthe medial post 106 can be shorter than the lateral post 108. The medialpost 106 can have a length L1 which is smaller than a length L2 of thelateral post 108. The difference in length provides a clearance for thepatellar tendon, as discussed below. The medial and lateral posts 106,108 can have cross-sections of equal or unequal size. Thecross-sectional area of the lateral post 108 can also be larger than thecross-sectional area of the medial post 106.

Referring to FIGS. 16-18, the medial receptacle 306 is also shorter thanthe lateral receptacle 308, such that when the alignment guide 300 ismounted on the tibia 80, a clearance gap 90 can be formed between thetibial tuberosity 82 and a free end 320 of the medial receptacle 306.The shorter length of the medial receptacle 306 of the alignment guide300 corresponds to the shorter length of the medial post 106 of thedrill guide 100, such that the clearance gap 90 can be maintained whenthe drill guide 100 is mounted on the alignment guide 300 for drilling,as shown in FIG. 19. The gap 90 provides a clearance for the patellartendon, while the medial and lateral receptacles 306, 308 of thealignment guide 300 stabilize the drill guide 100. Further, the medialreceptacle 306 and medial post 106 can be placed as close to thepatellar tendon as determined by the surgeon without obstruction fromthe alignment guide 300 or the drill guide 100, such that a drill pincan be passed through the medial post 106 without interfering with thepatellar tendon for drilling a hole on the tibial surface associatedwith the knee joint, or tibial joint surface for brevity. Drill pins canbe used to support cutting guides or other instruments for makingreactions as discussed in detail in U.S. patent application Ser. No.11/756,057, filed on May 31, 2007, the disclosures of which areincorporated herein by reference.

It will be appreciated from the above discussion that the presentteachings provide alignment guides and drill guides that can be usedtogether to provide tendon or other soft tissue clearance, whileproviding stability during drilling through the alignment guide.

The foregoing discussion discloses and describes merely exemplaryarrangements of the present teachings. Furthermore, the mixing andmatching of features, elements and/or functions between variousembodiments is expressly contemplated herein, so that one of ordinaryskill in the art would appreciate from this disclosure that features,elements and/or functions of one embodiment may be incorporated intoanother embodiment as appropriate, unless described otherwise above.Moreover, many modifications may be made to adapt a particular situationor material to the teachings of the invention without departing from theessential scope thereof. One skilled in the art will readily recognizefrom such discussion, and from the accompanying drawings and claims,that various changes, modifications and variations can be made thereinwithout departing from the spirit and scope of the present teachings asdefined in the following claims.

1. A device for an orthopedic knee procedure comprising: a drill guidehaving a body portion and first and second posts extending from the bodyportion, the first and second posts defining first and second internalthrough bores, the first post having a first cross-sectional shape andthe second post having a second cross-sectional shape different than thefirst cross-sectional shape of the first post.
 2. The device of claim 1,wherein the second post has a substantially keyhole-shapedcross-section.
 3. The device of claim 1, wherein the second post has asubstantially rectangular cross-section.
 4. The device of claim 1,wherein the first and second bores have circular cross-sections.
 5. Thedevice of claim 1, further comprising a patient-specific alignmentguide, the alignment guide including: a body with an inneranatomy-engaging surface shaped to closely conform and mate with acorresponding knee joint surface; and a single guiding receptacledefining an inner channel sized and shaped to non-rotatably receive thesecond post of the drill guide, wherein, when the alignment guide ismounted on the joint surface and the second post of the drill guide isreceived in the single guiding receptacle of the alignment guide, anexterior sidewall of the first post of the drill guide remains exposedand out of contact with the alignment guide and provides clearance for atendon associated with the joint surface, the first post at a fixedorientation relative to the single guiding receptacle.
 6. The device ofclaim 5, wherein the drill guide is non-rotatably mounted on thealignment guide according to a pre-operative surgical plan.
 7. A devicefor an orthopedic knee procedure comprising: a tibial drill guide havinga body portion and first and second posts extending from the bodyportion, the first and second posts defining first and second internalthrough bores with circular cross-sections, the first post having afirst cross-sectional shape and the second post having a secondcross-sectional shape different than the first cross-sectional shape ofthe first post; and a patient-specific tibial alignment guide, thealignment guide including: a body with an inner anatomy-engaging surfaceshaped to closely conform and mate with a corresponding tibial jointsurface; and a single guiding receptacle defining an inner channel sizedand shaped to non-rotatably receive the second post of the tibial drillguide, wherein when the alignment guide is mounted on the tibial jointsurface and the drill guide is connected to the alignment guide, thefirst post remains exposed outside the alignment guide and providesclearance for a patellar tendon, the first post at a fixed orientationrelative to the single guiding receptacle of the alignment guide.
 8. Thedevice of claim 7, wherein the second post has a substantiallykeyhole-shaped cross-section.
 9. The device of claim 7, wherein thesecond post has a substantially rectangular cross-section.
 10. Thedevice of claim 7, wherein the inner channel has a substantiallykeyhole-shaped cross-section.
 11. The device of claim 7, wherein theinner channel has a substantially rectangular cross-section.
 12. Thedevice of claim 7, wherein the alignment guide includes an arcuate armhaving a distal end engageable with the tibia.
 13. A device for anorthopedic knee procedure comprising: a tibial drill guide having a bodyportion and first and second posts extending from the body portion, thefirst and second posts having circular cross-sections, the first andsecond posts defining first and second internal through bores withcircular cross-sections, the first post having a longitudinal lengthshorter than a longitudinal length of the second post; and apatient-specific tibial alignment guide, the alignment guide including:a body with an inner anatomy-engaging surface shaped to closely conformand mate with a corresponding tibial joint surface; and first and secondguiding receptacles defining first and second inner channels sized andshaped to receive the first and second posts of the tibial drill guide,the first receptacle being shorter in length than the second receptacle,such that when the alignment guide is mounted on the tibial jointsurface and the drill guide is mounted on the alignment guide, the firstreceptacle and the first post define a clearance gap between the tibiaand the device for a patellar tendon.
 14. The device of claim 13,wherein the alignment guide further comprises an arcuate arm extendingfrom the body of the alignment guide.
 15. The device of claim 13,wherein the first post is positioned on a medial side of the tibia andthe second post is positioned on a lateral side of the first post. 16.An orthopedic method comprising: mounting a patient-specific tibialalignment guide on a tibial joint surface, the alignment guide includinga body with an inner surface shaped to closely conform and mate with thetibial joint surface, and a single guiding receptacle defining an innerchannel; engaging the inner surface to the tibial joint surface;positioning the guiding receptacle on a medial side of the tibial jointsurface; mounting a drill guide on the alignment guide, drill guidehaving a body portion and first and second posts extending from the bodyportion, the first and second posts defining first and second internalthrough bores, the first post having a first cross-sectional shape andthe second post having a second cross-sectional shape different than thefirst cross-sectional shape; non-rotatably inserting the second post inthe inner channel of the guiding receptacle; and placing the first postmedially and closely to a patellar tendon without interfering with thepatellar tendon.
 17. The method of claim 16, wherein the inner channelof the guiding receptacle includes a keyhole-shaped cross-section. 18.The method of claim 17, wherein the second post of the drill guideincludes a keyhole-shaped cross-section.
 19. The method of claim 16, theinner channel of the guiding receptacle includes a rectangularcross-section.
 20. The method of claim 19, wherein the second post ofthe drill guide includes a rectangular cross-section.
 21. An orthopedicmethod comprising: mounting a patient-specific tibial alignment guide ona tibial joint surface, the alignment guide including a body with aninner anatomy-engaging surface shaped to closely conform and mate withthe tibial joint surface, and first and second guiding receptaclesdefining first and second inner channels, the first receptacle beingshorter in length than the second receptacle; engaging the inner surfaceof the alignment guide to the tibial joint surface; positioning themedial guiding receptacle on a medial side of the tibial joint surface;mounting a drill guide on the alignment guide, the drill guide having abody portion and first and second posts extending from the body portion,the first and second posts having circular cross-sections, the first andsecond posts defining first and second internal through bores, the firstpost having a longitudinal length shorter than a longitudinal length ofthe second post; inserting the first and second posts in thecorresponding first and second inner channels of the guidingreceptacles; and providing a clearance between a tibial tuberosity andthe first receptacle and first post for a patellar tendon.
 22. Themethod of claim 21, further comprising drilling through the first postwithout interfering with the patellar tendon.